Bug when making a transfer - typing numbers switched pages

Hello, I looked up the forum and I haven't found such problem. I faced following bug in Vivaldi browser when I wanted to make a transfer: I did it via https://www.bph.pl/pi/do/Login . I entered a standard page with a form that had some blank spaces to be filled in. When I typed a number of money that needed to be transfered, the page switched to another. I found that typing zero('0') zooms the page in(like Ctrl+mouse scroll), nine('9') zoomes out and backspace changes the actual tab. I was afraid to try more. Finally, I had to change browser in odrer to do what I needed. Letter characters(a, b, c, A, B, C etc.) work properly. The mouse works properly too. The bug appears also while trying to type the main password by keyboard. After logging in again, the bug is each time the same. I use Windows 7 Professional, Service Pack 1. I think it can be important to fix such bug. I'm sorry for my bad English.

Not a standard form, I suppose that's the cause there. If they recognize the cursor is in a form field they disable the shortcuts (1-4 switch tabs in various orders, 6-0 zoom by varying amounts), but as it isn't a standard form field the shortcuts aren't disabled.

Probably related to a known bug, VB-3177, but I can't say more about it than that.